The present invention relates generally to a method of manufacturing pharmaceutical dosage forms, for human or veterinary use, preferably sustained release particles, such particles having diameters ranging from 0.1 to 3.0 mm. Such particles may contain analgesics, such as morphine, or other active ingredients. The present invention also relates to dosage forms obtained by processing of the aforesaid particles, such as tablets, suppositories or pessaries.
In our co-pending British Patent Application No. 9404928.5 we describe a process for the manufacture of particles, preferably sustained release particles, which comprises
(a) mechanically working in a high-shear mixer, a mixture of a particulate drug and a particulate, hydrophobic and/or hydrophilic fusible carrier or diluent having a melting point from 35 to 150.degree. C. and optionally a release control component comprising a water-soluble fusible material or a particulate, soluble or insoluble organic or inorganic material, at a speed and energy input which allows the carrier or diluent to melt or soften whereby it forms agglomerates;
(b) breaking down the agglomerates to give controlled release particles; and optionally
(c) continuing mechanically working optionally with the addition of a low percentage of the carrier or diluent; and optionally
(d) repeating steps (c) and possibly (b) one or more times.